Siemens LOGO! - Page 162

LOGO! Manual
A5E00380835-01
154
Timing diagram
En
T is
busy
Q
T
L
T
H
The bold section of
the timing diagram
also appears in the
symbol of the random
generator.
Functional description
The 0 to 1 transition at input En triggers a random on-delay
time between 0 s and T
H
. The output is set when the on-
delay time has expired and if the signal at input En remains
hi at least for the duration of this time.
The time is reset if input En is reset before the on-delay
time has expired.
A 1 to 0 transition at input EN triggers a random on-delay
time between 0 s and T
L
.
The output is reset after the off-delay time has expired, pro-
vided input En remains lo at least for the duration of this
time.
The time is reset if the signal at input En changes to 1
again before the off-delay time has expired.
The time expired is reset after a power failure.
LOGO! functions